Enhanced ferroelectric photovoltaic performance of Bi2FeCrO6 thin films for neuromorphic computing applications

Nowadays, ferroelectric photovoltaic synapses have attracted great attention due to its polarization controllable and self-powered features. However, the large bandgaps of ferroelectric oxide materials limit its application. This study focuses on the enhancement of ferroelectric photovoltaic properties and the synaptic application of Bi2FeCrO6 (BFCO) device. It is found that the bandgap of BFCO can be modulated by Cr alloying, which causes its photovoltaic effect in the visible region to exceed that of BiFeO3 (BFO) significantly. The short-circuit current density (J(SC)) of BFCO device in the visible region increases by about 100 times than that of BFO. Furthermore, the polarization modulation and multi-states response are demonstrated by an external electric field. For BFCO ferroelectric photovoltaic synapse, long-term potentiation/depression (LTP/LTD) measurements show an excellent synaptic plasticity of the polarization modulation. The simulated image recognition rate using the MNIST dataset reaches a high accuracy of 96.06%. This work has expanded the potential application of ferroelectric photovoltaic synapse in the visible region.